Safety helmet



FIG. 1 is a perspective view showing the new design for a helmet;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is a side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

Portions of the drawings shown in broken lines do not form an essential part of the design. 

CLAIM The ornamental design for a safety helmet, as shown and described. 